Rihanna's Halloween Party at Greystone Manor | Pictures

Rihanna was last night's queen of the annual West Hollywood Halloween Carnaval. The singer was awarded a crown and a key to the city by the mayor at Greystone Manor nightclub, before heading inside to host an All Hallows' Eve bash with famous friends including Flo Rida and Paris Hilton. Rihanna skipped a costume for the festivities, instead opting for a black dress and heels, but was happy to pose with fellow partyers in their full regalia.

Rihanna took the night off work to focus on revelry, but the pop star isn't slowing down on the career front any time soon. This week, she announced that she's planning what she calls her 777 tour, where she'll play seven shows over seven days in seven different countries. The concert series kicks off mid-November, timed to the release of her upcoming studio album, Unapologetic. Rihanna also made headlines earlier this week when news that a special, limited-edition box set of Unapologetic will run fans $250.